hellee



(No Model.) V

E. I. HELLER.

ARTIFICIAL MILLSTONE 0R BURR. No. 844,902. Patented July 6, 1886 WJMATTORNEY rrnn STATES PATENT OFFICE.

EMANUEL I. HELLER, OF IGLAU, AUSTRIA-HUNGARY.

g ARTIFICIAL MILLSTONE OR BURR.

EPEC'IFIGATION forming part of Letters Patent No. 344,902, dated July 6,1886.

Application filed January 30. 1886. Serial No. 190,267. (No model.)

To all whom it may concern.-

Be it known that I, EMANUEL I. HELLER, a subject of the Emperor ofAustria Hungary, residing at Iglau, Austria-Hungary, have invented a newand useful Improvement in Artificial Millstones or Burrs, of which thefollowing is a specification.

These artificial millstones consist of, first, sharp, broken, andassorted grains of quartz, quartz-crystal, or NaXos-corundum emery ofvarious grades and proportions of weight, ac cording as the product isto be fine, coarse, hard, soft, medium, or superfine; second, magnesiteor dolomite, or any other known solid mineral uniting material; third,dissolved magnesium chloride or soluble glass,

, or a similar known liquid chemical uniting agent. These three mainconstituents can be united in various quantities, according as the massis desired to be fine, coarse, hard, soft, dense, or porous, and byusing quartz or quartz-crystal, or Naxoscorundum emery, three differentgrades of stone are produced. These ingredients are so mixed that eachgrain comes in contact with magnesite or dolomite, or other knownsuitable uniting agent, and with magnesium, chloride, or sol uble glassor other known and suitable liquid uniting agent, and in this way thecombination sets. By the suitable addition of the said liquid unitingagent-sueh as magnesium chloride, soluble glass, &cwhich, according tothe weather, whether dry or moist, amounts to twelve to thirty per cent.of the whole weight of the said mineral grains and pulverized unitingagent, the whole of the uniting agent remains in such contact with thegrains that the spaces formed between the sharp-edged grains-that is,the poresshall not be filled up with cement, but remain open when themillstones are formed by stamping or pressing. By this process I obtaina porous stone, whereby I entirely obviate dressing the millstones, asthe edges of the single grains sharpen themselves by reason of theporosity of the stone when they wear off. The millstones are formedaccording to this process, and in the following manner, using the moldor apparatus shown in the drawings, in which- Figure l is a perspectiveview of the mold, and Fig. 2 the finished stone, with exhaust channelsand sails.

For millstones without exhaust-pipes, the above-described mass isintroduced into the mold shown in the drawings, A B O P, and afterwardstamped or pressed.

For millstones with automatic ventilation, the cores E are set up in themold A B G I. These cores can be of any desired number or shape,straight, crooked, worm-shaped, 850., and in anyposition, and may bemade of wood, iron, porcelain, 85c.

Instead of the cores'E, pipes of various materials can be made, whichare to remain in the stone, or the automatic exhaust-pipes can be cutout of the finished stone in various shapes.

After molding the millstone the mass remains in the said mold till it issolid--that is, as hard as stone, and can be removed from the mold.Above each of the pipes is fastened a wind-sail, and according to therotation of the stone will either introduce cool air from the outside tothe grinding-surface or remove the warm air arising from the friction ofthe stone.

A is the molding-plate. B designates the stone-drum; C, the perforateddrum; D, the adjusting-support; E, exhaustchannel core or mold 5 L, theexhaust-channel; M, the windsail; I, the central shaft.

I am aware that it is not new to make artificial millstones by mixingquartz, quartzerystal, or NaXos-corundum emery with magnesite, ordolomite, or other known solid mineral uniting agent and a solution ofmagnesium chloride or soluble glass or other liquid chemical unitingagent, and then stamping the mass in a mold; and I therefore do notclaim the same; but

I claim- 1. In combination with the molds. A B, the cores E, for thepurpose of producing exhaust-passages in an artificial millstone,substantially as set forth.

2. The wind-sails M, in combination with the millstones havingexhaust-channels, substantially as set forth.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

EM. IG. HELLER.

WVitnesses:

CARL SARRER, BUDOLF FILIP.

